This invention relates to a signal detector circuit for a high-speed receiver. More particularly, this invention relates to a signal detector circuit that operates asynchronously of the received data and at a lower frequency, but nevertheless detects with high-precision the presence of incoming data.
High-speed receivers, such as are used in 10 Mbps (i.e., 10BASE-T) and 100 Mbps (i.e., 100BASE-T) Ethernet applications compliant with the IEEE 802.3 standard, gigabit Ethernet (i.e., 1000BASE-T) applications (IEEE 802.3ab), and 10 Gigabit Ethernet (i.e., 10GBASE-T) applications (IEEE 802.3an), are frequently idle, insofar as there may not be incoming data to process. (All references herein, including in the claims that follow, to any IEEE standard, is a reference to the version of that standard current on the filing date hereof.) It therefore would be desirable to be able to turn off such a receiver—e.g., to conserve power—until such time as incoming data are present. However, if the receiver were turned off, it would be desirable to be able to reliably turn on the receiver when data begin to arrive.